Rotary pad machines, or floor maintenance machines, are fast and efficient for performing a variety of tasks. Rotary pad machines can be used for buffing, scrubbing, burnishing, polishing and other floor maintenance applications. Usually, a rotary pad machine has a drive shaft that rotates a pad driver disc. Attached to the pad driver disc is a pad used to clean or maintain the floor. A rotary pad holder holds the pad to the pad driver disc.
Rotary pad holders are well-known for centering and holding a floor maintenance pad to a pad driver disc of a rotary pad machine. Typically, these rotary pad holders have two pieces with mating threads. The first piece is fixed to the pad driver disc, and the second piece is threaded to the first piece to hold the pad between the first and second pieces in a centered position on the pad driver disc. The second piece is uncoupled by unthreading to replace the pad.
When using a rotary pad machine, the operator will frequently have to replace pads due to wear or to use a pad with different abrasive characteristics. Often, the operator of a rotary pad machine will not be equipped with tools to change the pads. For a number of pad holders, no tools are needed because the second piece can be unthreaded from the first piece by turning the second piece by hand. However, unthreading the second piece of the rotary pad holder from the first piece can be time-consuming. In addition, the operator of a rotary pad machine may have to make frequent adjustments to the pad holder because a pad is slipping or not being correctly held in place by the rotary pad holder. Because of frequent changes and adjustment of pads, there is a need for a pad holder with a quick release mechanism so that pads can be changed or adjusted, quickly and easily, without the use of tools and without requiting unthreading.
As mentioned above, unthreading a pad holder device can be time-consuming. However, the threaded connection in pad holder devices can result in other problems as well. For example, the threading is usually left-handed or right-handed depending on the direction of rotation of the pad driver disc. The thread direction is chosen such that the resultant torque on the pad holder, when the rotary pad machine is in use, tends to tighten the threaded connection. Therefore, operation of the rotary machine tends to hold the pad in place rather than unthreading and releasing the pad. However, the torque can often tighten the rotary pad holder so much that it is extremely difficult to remove when the operator wants to change floor pads. Furthermore, as disclosed in Malish, U.S. Pat. No. 5,400,461, rotary pad holders sometimes loosen during floor maintenance operations. Thus, there is a need for a rotary pad holder that will neither loosen nor tighten during operation of the rotary pad machine.
Some rotary pad machines have two pad driver discs rotating in opposite directions. For these machines, it is necessary to use one left-handed threaded pad holder and one right-handed threaded pad holder. The right-handed threaded pieces and left-handed threaded pieces of the pad holders are not interchangeable. Thus, for spare pans and supply purposes, it is necessary to keep both right-handed threaded and left-handed threaded pieces in stock. In addition, for manufacturing purposes, it is necessary to have equipment to manufacture both left-handed threaded pieces and right-handed threaded pieces. There is a need for a rotary pad holder that uses the same pans for clockwise-rotating pad driver discs and counter-clockwise-rotating pad driver discs.
There are at present a wide range of floor maintenance pads available for use on rotary pad machines. These pads must be of different materials, abrasiveness, and structure to perform the many functions required of floor maintenance machines such as buffing, scrubbing, and polishing. Furthermore, these pads are of varying thicknesses. Thus, there is a need for a rotary pad holder that can be adjusted, quickly and easily, to accommodate pads of varying thicknesses.
Smith, U.S. Pat. No. 4,888,843, describes a rotary pad holder in which a top piece of the pad holder includes internal, continuous threads which are engaged by matching threads, or portions of threads, on a bottom insert. The bottom insert is pressed into place on the top piece, and the insert may be rotated to tighten the pad into place or to remove the insert so the pad may be replaced. While the Smith pad holder accommodates pad of different thicknesses, the two pieces described by Smith can rotate relative to one another. Thus, the problem of over tightening and over loosening is not solved. Also, the Smith patent does not teach a quick release mechanism because the bottom piece in Smith must be unthreaded from the top piece to change pads.
Malish, U.S. Pat. No. 5,400,461, describes a rotary pad holder which is threaded into place and includes detents which pop out and match into indentations in the lower piece when the two halves are screwed together. The detents prevent over tightening of the pad and lock the pad into place. However, the detents in the pad holder produced in accordance with the patent have been known to release as a result of the torque applied by the rotary pad machine and over tightening is not always avoided. Moreover, the rotary pad holder described in Malish is difficult to disconnect because it requires the lower piece to be unthreaded from the upper piece in a similar fashion to the rotary pad holder described by Smith.
Thus, the prior art shows a need for a rotary pad holder which holds and centers a pad to a rotary pad machine and has a quick release mechanism for changing pads. The prior art also shows a need for a rotary pad holder which accommodates pads of different thicknesses and does not require tools for changing the pads. The prior art further shows a need for a rotary pad holder which has consistent parts independent of the rotational direction of the pad driver disc and neither loosens nor tightens during use. The needs outlined above led to the present invention.